1 Introduction

These are some tips to help you train for your first 100-mile race. This is a tough distance; it is hard to overstate the difficulty that is faced. This difficulty is compounded by the fact that there is little lore around training for a 100-mile race. Ultrarunning is where marathon running was in the 70's; an emerging sport. Today we have a vast number of marathon training plans to choose from, and maybe one day there will be a similar number of ultramarathon training plans. Until then, there are just some personal opinions, such as this.

Note that this article is focused on training for the 100-mile race. You should read Essential Ultrarunning Tips and the other ultra specific tips as well.

1.1 Training Plans for 100-Milers

This is not intended to be a training plan, but rather tips to help you move from shorter ultramarathon distances to the 100-miler. These tips are not universal in nature; they are ideas that you should consider and use your best judgment in how to use them. See Ultramarathon Training Plans for selected plans.

1.2 Individuality

Each runner is different and will have different strengths and weaknesses. Not all of these tips will apply equally to all runners. For instance, someone able to finish the 100 miles in 16 hours may not have an issue with sleep deprivation. Each runner's experience may also change in different races; what works in one race may not in another. However, I believe most runners may benefit from most of these ideas. See Individuality and the Experiment of One.

1.3 Acknowledgements

I'd like to thank Fred "Doom" Dummar and XtremeTaper for their help with this article.

2 Low Mileage, High Quality

I highly recommend running only four days a week (see How Often To Run) when training for any distance. Each of your runs should have a purpose, and the purpose should not be the simple addition of miles. You should understand Supercompensation and why doing a 16 mile run and having the next day off is far better than running 8 miles a day.
This is especially true for 100-mile races. Running high weekly mileage in itself will not help you prepare. Running 5 miles, three times a day, seven days a week will just wear your body out, without producing significant endurance.
The weekly mileage you do may be considered high as a consequence of your long runs, but this should not a goal. I consider myself a 'low mileage, high quality' runner even though I do 90-100 miles per week.

3 Long Runs

This is core of your preparation, as it is for any endurance race. For most people, it is impractical to do very long training runs (> 50 miles), and the benefits are unclear (they may help, but so few people do these runs, there is not even much anecdotal evidence). This means that for a 100-mile race, training runs will be a much smaller percentage of the target distance. Consider the fact that doing a 60 mile training run for a 100-mile race is the same percentage as doing a 16 mile training run for a marathon. Instead, most people use a combination of ‘ordinary’ long runs with ‘ultra-long’ and ‘doubles’. Different people use different approaches based on lifestyle, background, etc.

Ordinary. This is continuing the long runs you built up while training for your shorter ultramarathons.

Ultra-long runs. This is an extra long run that is performed periodically; for instance, 30-40+ mile runs every 2-3 weeks is a common suggestion. I have used extra long runs not only to build endurance, but to practice for the race. I will practice things like run/walk patterns, what to eat, etc. Doing the ultra-long runs more frequently is better, but time constraints may make that impractical. A shorter ultra can work well as preparation for a 100-miler. (If you have not completed several shorter ultramarathons, I would advise against trying a 100-miler.)

Doubles. Running two long runs close together helps create some of the training stress of a longer run. For instance, I’ve done a 20 mile run followed by a 30 mile run the next day, or a 20 mile run in the morning followed by another 20 mile run in the evening. You can do three long runs close together, but be very careful that you don't push your body too far.

4 Overnight Runs

For most runners, a 100-mile race will last for most, if not all, of the night. It is critical to prepare for this overnight section. You should aim to do at least one run that lasts most of the night, ideally from dusk to dawn. In preparation for this, you should do a few runs in darkness, so that you work out the logistics of lights, etc. (See Running in the Dark) The overnight run will help prepare you for the sleep deprivation and psychological difficulty. Pace for the overnight run is not critical - it is better to walk for most of the night than to run for just some of it.
It is also sometimes helpful to change your mental outlook while running at night. Being the meanest (or fastest) thing in the woods might be a beneficial way to approach your running through the woods at night.

6 Walk

It seems that walking should be easy, but this is not the case in a 100 mile race. If you walk only 20% of the race, you still have to walk 20 miles. If you have not trained to walk, the walking part of the race may cause unexpected problems. Walking uses different muscles, and puts different stresses on the foot. With practice, you can improve your walking speed significantly. You do not need to learn to race walk, but being able to walk 20+ miles at 15-20 min/mile pace will help greatly.

7 Eating

Foods that taste good in a marathon or even a 50 mile race will likely not work for you in a 100 mile race, unless you are extremely lucky and well trained. Most racing fuels (Gels, etc.) and drinks (Gatorade) for the marathon and shorter distances are digested very fast, and while some are better than others, all will turn your digestive system acidic over time. An acid stomach will cause you to slow your intake of fuel or may lead to vomiting, etc. You can take care of your stomach with small amounts of fat, and protein to maintain the PH of your intestinal tract. The amount and types of protein and fat is highly individual as is the time to start introducing them into your race fueling strategy, so you will need to experiment on your longer runs to determine what works for you.

8 Practice Races

Before contemplating a 100-mile race, you should have completed a number of shorter races in the 40 mile to 100K range. This will give you experience not only of running that distance, but the logistics of racing. A race that you will complete after sunset is especially beneficial, as the transition to darkness can be hard logistically and psychologically.

9 Speed work

It sounds strange to include speed work when thinking about a 100-mile race, but it is still important. A little speed work will allow you to run faster with the same perceived effort. That means you spend less time in the race. That's less footsteps, which reduces the stress on your body and the likelihood of blisters. Being faster also means a lower heart rate at a given pace. Lowering your heart rate makes digestion easier, which is critical.

10 Practice

You should look to practice as many aspects of the race as possible.

Try to run on similar terrain (ideally the course itself).

It is critically important to practice eating.

Practice running overnight.

If the race is at altitude, you need to acclimate and train at altitude.

Look for anything you can do to recreate aspects of the race.

11 Understand what it takes to finish

A 100-mile runner finishes with a tough mental outlook (run at night), with strong feet, and by fueling the machine. If you know you will not quit, have overcome obstacles like navigation errors and fear of the woods at night, can keep your feet from becoming blistered to the point of keeping you from moving, and can keep fuel and fluids going into your body then you will finish.